Improved ore-roasting furnace



geiten 4fates jatat @ffice GEORGE B. FIELD, 0F NEW YORK, N. Y. Letters Patent No. 68,058, dated August 27, 18,67.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, GEORGE B. FIELD, of the city, c ounty, and Stateof New York, have invented a new and improved Ore-Roasting Furnace; and I do hereby declare the following to be a full, clear, and exact description of the saine, reference Vbeing had to the accompanying drawings, forming part of this specification, and in whiclw-` Figure 1 is a top view of my invention, a portion of the cylinderAbeing removed to show the shelf within.

Figurc is a horizontal' section of my invention, cutting the shelf through its smaller diameter.

Similar lettcrsof reference indicate corresponding parts in the two figures.

This invention consists in the use of a-peculiar-shaped ledge or shelf in the furnace, made hollow for the introduction of steam or water, and the construction of an aperture or port, through which the cavity of the shelf may bc cleaned from thc ont-side of the revolving cylinder.

The patent for which this application is made will, if granted, be in a measure supplementary to that applied for by your petitioner June 6, 1867, upon ore-roasting furnaces.

In all ore-roasting furnaces one great desideratum is to obtain a perfectly equal distribution of the heat to the ore, and a thorough agitation of the contents of the cylinder in which the ores are roasted. To accomplish these two purposes various devices have hitherto been resorted to, such as the use of a Worm or revolving screw, agitating-rakes, &c. All these devices are objectionable for various reasons, among which may be mentioned the following :V` they do not thoroughly effect the object sought to be accomplished; they necessitate the introduction of additional machinery to operate them, and thus render the whole apparatus complicated and expensive; subjected as they arc-to an intense heat, and operating against heavy masses of mineral, theysoon get out of repair; they ll up the space inside ofthe cylinder. All these imperfections in the ore-roasting furnaces, as heretofore constructed, I propose to obviate, simply by the form and position'of a. ledge or shelf inside of the cylinder, the ledge'or shelf being made hollow, for the admission of water or steam to cool it and prevent its rapid dcstructionby heat. Y

Inordcr that others skilled in the art to which my invention appertains may be enabled to malte and use the same, I will proceed to describe it in detail. i i

In the drawings A represents the outside shell of the cylinder of aievolving ore-roasting and desulphurizing furnace. '.lhe apparatus by which it is caused to revolve is .not necessary to be here shown.. Inside of the cylinder A is a hollow ledge or shelf, B, composed of two parts b b', united by pipes ce', through which comd munication is .had between the parts b and b. The form of the whole shelf thus constructed is `that of Van ellipse, having a longitudinal slot, d., through its centre, across which run the pipes c c. The shelf thus made is placed in the cavity of the cylinder in a diagonal position, as shown in the drawings, a space being left betweenits extremities and the ends of the cylinder, and is bolted firmly in this position. At E E apertures are provided snciently large and of the proper shape for the introduction of a rake or scraper, by which to scrape and clean the interior of the shelf B, when, by reason of the impurities of the lwater, it may have become foul. Valves or plugs e e are provided' for closing these apertures, when the process of cleaning the shelf is not going on. F is the pipe, through which the water or steam is introduced to the interior of the shelf,and Gr is the exhaust or outlet. To secure the circulation ofthe water in the shelf one of these pipes must communicate with the plate b, and the other with b at the opposite end oil the shelf.

In a furnace thus constructed the ores are placed in the cylinder A, and the latter is caused to revolves. Theh'eat is received at rst at one end of the cylinder, though, after awhile, the heat caused by the combustion of the liberated sulphur of the ores may be sufficient, and the furnace may be disconnected'from they cylinder. When Vthe cylinder reaches a'certain point in its revolution the shelf B becomes V.an inclined plane, upon which the ore slides tothe lower end and falls through the space between it and the end of the cylinder, lodging upon the bottom of the cylinder. When the cylinder has revolved half round, this end of the shelf becomes elevated. and' the opposite end depressed, and, the ore slides back upon the plate and falls through the space-at its end t0 its former position. Another half revolution repeats the process, and so on indefinitely. Some of the orc will fall through the central slot of the shelf. As the cylinder revolves and the shelf is inverted this will be caught and carried with the rest of the ore to the lower end of the shelf. i

'sa oss 2 By this means the ore is' thoroughly pulverized, while at the same time its position in the furnace is constantly changing, so as to subject every part of it to the heat alike.

Hoving thus described my invention, what I cla-im as new, and desire to secure by Letters Patent, is- 1. The plete or shelf-B, made hollow for the admission of water o1' steam, and vcomposed of twopzirts, band Z1', connected by the pipes c c', when constructed and used snbstan tially :is and for the purpose speciied.

' 2. The orifices E E in hollow shelves, used in the inside of revolving orc-roasting furnccesfor the purpose of clennin` the internal chambers of the shelves, substantially as described.

GEO. B. FIELD. Witnesses WM. F. MeNAMARA, JAMES H. GnIDLnY. 

